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<table width="100%" summary="page for Mites"><tr><td>Mites</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Mites and Wilt Disease</h2>

<h3>Description</h3>

<p>Data from an experiment to test whether exposure to mites protects against Wilt Disease in
cotton plants.
</p>


<h3>Usage</h3>

<pre>
data(Mites)
</pre>


<h3>Format</h3>

<p>A data frame with 47 observations on the following variables.
</p>

<ul>
<li><p><code>treatment</code> a factor with levels <code>mites</code> and <code>no mites</code>
</p>
</li>
<li><p><code>outcome</code> a factor with levels <code>wilt</code> and <code>no wilt</code>
</p>
</li></ul>



<h3>Details</h3>

<p>Researchers suspected that attack of a plant by one organism induced resistance to subsequent attack by a different organism.  Individually potted cotton plants were randomly allocated to two groups: infestation by spider mites or no infestation.  After two weeks the mites were dutifully removed by a conscientious research assistant, and both groups were inoculated with Verticillium, a fungus that causes Wilt disease.  More information can be found at <a href="https://www.causeweb.org/webinar/activity/2010-01/">https://www.causeweb.org/webinar/activity/2010-01/</a>.
</p>


<h3>Source</h3>

<p>Statistics for the Life Sciences, Third Edition; Myra Samuels &amp; Jeffrey Witmer (2003), page 409.
</p>


<h3>Examples</h3>

<pre>
data(Mites)
if (require(mosaic)) {
  tally(~ treatment + outcome, data=Mites)
  tally(~ outcome | treatment, format="percent", data=Mites)
}

</pre>


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